说明：  在二维空间里有两个点A=(X1，Y1)和B=(X2，Y2)，如果X1>X2并且Y1>Y2 ，我们认为A优于B，A是这个集合的最大极值点，在给定的二维空间里的N个点的集合S中，找出最大极值点。
(In two-dimensional space, there are two points = A = (X1, Y1) and B (X2, Y2), if the X1 and Y1 > X2 > Y2, we think that A is superior to B, A is the biggest extreme value point of the set, in A given set of N points in the two-dimensional space S, find out the most extreme value point.)